tHE woman accused of stabbing teenager Casey Kearney replied, ‘You’re joking’ when a detective told her the 13-year-old had died.

Hannah Bonser, aged 26, denies murdering Casey, who was stabbed as she walked through Elmfield Park, Doncaster, on Valentine’s Day.

A jury at Sheffield Crown Court was played CCTV footage of Bonser being informed that Casey had died.

Prosecutor Graham Reeds QC said her demeanour changed when a detective told her of Casey’s death.

In a statement, Det Con Gary Edwards said: “Her face appeared to flush, she looked down, she rocked backwards and looked back up. It was very subtle but her demeanour changed.

“Then she said to me, ‘You’re joking’. She was very quiet and there was a marked difference in her demeanour. She didn’t maintain eye contact or smile. Her face was flushed, her eyes watered - she didn’t actually cry but she appeared upset.”

Jurors heard from psychiatrist Dr John Pilgrim, who assessed whether Bonser, of St James Street, Doncaster, was fit to be interviewed by police.

He described her as ‘bewildered’ and ‘stressed’, adding: “She told me she knew she had stabbed a girl in the park with a knife. She didn’t know why she had done it and she hadn’t intended to harm anyone.

“She didn’t know why she had the knife with her but said she had been hearing voices in her head ‘ranting and raving’.”

Dr Pilgrim said Bonser wasn’t suffering from psychosis at the time of the assessment, but told him she felt ‘like she was in a dream’ and ‘like I’m not there’.

“Those are symptoms that individuals experience at times of extreme stress,” he added.

He said Bonser had previously been sectioned under the Mental Health Act.

In a statement, housing worker Hannah McDanielson described visiting Bonser at her home in early February.

She said: “Hannah told me she smoked cannabis. She kept saying she needed to be locked up and her friends were reluctant to be with her because she lashed out without warning.”

Bonser told the worker, ‘One day I’m going to blow up’.

“When I asked her what she meant she said she didn’t know, but that people in her area were ‘out to get her’.”